Although there is considerable evidence that cochlear implants can result in significant audiological psychological benefit for postlingually deafened adults and prelingually deafened children, that same evidence indicates there is extreme variability in the outcomes. To determine the factors that contribute to this variability, preimplant psychological variables will be studied. For the postlingually deafened adults, cognitive measures and participatory compliance measures are emphasized. Previous work in this laboratory has demonstrated that these variables are potentially useful predictors of implant outcomes, but replication is required before their clinical utility can be assumed. Additionally the new generation of implants offers the possibility of optimally fitting the speech processor to the subject. In a sample of such optimized fittings, it is possible that psychological variables may account for even more variance in implant outcome. The proposed research is designed to assess that possibility. Predicting the outcome of implants with children requires understanding the role of parents as well as the role of child specific variables. The present research will examine the role of both factors in the use and outcome of cochlear implants with prelingually deafened children. In addition to audiological outcomes, the prospect of improving the "quality of life" of implant recipients is another justification for their use. To determine the impact of implants on quality of life, a set of psychological variables were selected on the basis of existing research on the psychological status of post-lingually deafened adults and prelingually deafened children. These variables will be assessed in a longitudinal design and changes will be related to the audiological outcome of the implant.